Functionalized nanoparticle transforms “cold” to “hot” adenoid cystic carcinoma of salivary gland tumour microenvironment in vitro

ABSTRACT Adenoid cystic carcinoma (ACC) of salivary gland is a “immune-cold” tumour. Annexin A3 (ANXA3) is an apoptotic protein found to be participating in immune cell infiltration in tumour microenvironment (TME) of various cancer cases. Significant low expressions of ANXA3 protein found in adenoid cystic carcinoma. We hypothesized overexpressing ANXA3 transforms ACC “cold” TME to “hot”. We cultured UM-HACC-2A and UFH2 spheroids on extracellular matrix and co cultured them with peripheral blood mononuclear cells. We functionalized FDA (The Food and Drug Administration) approved Poly(lactic-co-glycolic acid) PLGA nanoparticles with anti-cMyb antibody and ANXA3 recombinant protein using streptavidin-biotin conjugation. Upon overexpressing ANXA3 in ACC spheroids in immune coculture model using functionalized nanoparticles, significant increase of tumour infiltrating lymphocytes and decrease in the size of the ACC spheroids observed. Apoptotic profiler assay further confirmed significant upregulation of apoptotic proteins, some of them participate in immune infiltration. Overall, this project exhibits promising results showing potential approach to convert ACC into an immune “hot” tumour. Competing Interest Statement The authors have declared no competing interest.